Treatment of scrap iron or steel.



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MALCOLM MCDOWELL, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO THE FORT DEARBORN IRON COMPANY, OF SAME ,PLAGE.

TREATMENT OF SCRAP IRON QR STEEL.

SPECIFICATIQN forming part of Letters E atent hlo. 644,719, dated March 6, 1900. Application filed October 28, 1896. Serial No.'610,262. (No specimens.)

To all w/wm it Hwy concern:

Be it known that I, MALCOLM lrtcDoWEL'L, a citizen of the United States of America, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Process in the Treatment of Scrap Iron or Steel, of which the following is a description. r

In the treatment of scrap ironor steel to re reclaim it for further use it is desirable, in order to assure the best results, that each and every part or portion of the mass shall be subjected to a similar treatment and to an equal extent, the object being to so treat :5 the scrap that it will result in a homogeneous mass of a uniform nature, which will be an average of the natureof all the individual pieces going to make up the entire charge.

, My invention has in view the above desir- .2o able objects; and to this end it consists in the y will be unnecessary. The scrap is then placed in a tumbling-box and tumbled to clean it by 3 5 removing as much of the dirt and the oxids (black and red) as is possible by that process. In this step I'also prefer to introduce a blast of sand into the box through the hollow journal of the same to aid in thoroughly clean- 40 ing the scrap. I then select a sufficient quantity of the out and cleaned material fora satisfactory charge say from twelve hundred to fifteen hundred poundsand charge it, together with a proportionate amount of a flux 5 which fuses at a low temperature, into a rotary heating and welding furnace. Suflicient heat is then applied to reduce the flux to a liquid f0rm, and 1 as the scrap is rofled over by the rotary motiT of the furnacefwhich motion carries it well. up the sides, allowing it to fall back into the ffux, it becomes enveloped with the same, protecting it from oxidation. The furnace heat is then gradually raised to the highest-point necessary to insure the. equalization of all the inequalities existing by reason of the individual nature of each piece,of scrap composing the charge under treatment. For the reason that the material charged in the furnace has been thoroughly cleaned of its dirt and especially from the oxids. that enveloped it the charge of scrap will, at a'comparatively-moderate temperature, become welded into a mass or dinarily by first intent, the flux enveloping it protecting it while it is being brought to a uniform nature, as before stated. This is made manifest when the resulting ball has been subjected to pressure bybeing passed through a squeezer or under ahamrner-by its emerging a solid homogeneous bloom or billet of metal. From this point the bloom or billet may be handled in the same manner as when produced by other processes.

By dividing the scrap intogrades depending upon the size of the individual pieces, as be fore mentioned, it is clear that the process may be more uniformly conducted throughout. The heat may be more uniformly regulated to treat the entire mass, and each piece will require and receive substantially the same treatment and degree of heat to reduce it to a=proper welding condition, thus lessening any liability that might exist that the bloom mightnot be of a uniform quality or nature throughout. '85

By cleaning the scrap of dirt and the oxids, as :described, it can be brought to a welding 'condition at a much lower temperature, while by enveloping each piece in the flux I am enabled to raise the furnace heat to the highest temperature necessary to secure per- 7 WWW I prefer to use the decarbonizingflnx of ferrosilicate of manganese. If the bloom is to be of steel, I prefer to use the carbonizing flux of ferrocarhureted silicon and manganese. In either case the action of carbonizing or decarbonizing may also be materially aided by using a carbonized flame or an oxidized fia me to heat the furnace. The degree to which the carbonizing or decarbonizing shall be carried always depends upon whether the charge is of scrap iron or of steel. Consequently the percentage of flux used may vary slightly. I have, however, secured very good results in a charge of scrap of twelve hundred and fifty pounds by using substantially ten per cent, by weight, of lthe flux-that is to say, substantially one hundred and twenty-five pounds; but I do not limit myself to an exact quantity of the fi ux-, as it'will necessarily vary somewhat, as stated.

In all cases the produce will be a solid homogeneous bloom of metal of a uni form quality throughout.

Having thus described my invention, what I claim as new, and desire to-secure by Letters Patent, is-

1. The herein-described process of treating scrap iron or steel, consisting in first reducing the scrap to smallpieces, then freeing the same from dirt and oxids, then charging the cleaned scrap together with a flux into a heating and welding furnace and so manipulating the same that the charge will be alternat-ely plunged into and lifted from the flux, preventing rapid oxidation, meanwhile subjecting the same to a temperature sufliciently high to reduce it to a homogeneous mass or ball, and then removing the ball and subjecting it to pressure by squeezing or hammering to produce a bloom or billet, substantially as described.

2. The herein-described process of treating scrap iron or steel, consisting in first re-' ducing the scrap to smallipieces, then freeing the same from dirt and oxids, then separat- 5 ing the scrap into grades dependent upon the size of piece, and treating each grade separately by. charging a suitable quantity of the same together with a flux into a heating and welding furnace and so manipulating the same that the charge will be alternatelyplunged into and lifted from the flux, preventing rapid oxidation, meanwhile subjecting the same to a temperature sufficiently high to reduce it to a homogeneous mass or ball, and then removing the ball and subjecting it to pressure by squeezing or hammering to produce a bloom or billet, substantially as described.

3. The herein-described process of treating scrap iron or steel consisting in first reducing the scrap to small pieces and freeing the same from dirt and oxids, then separating the same into grades dependent upon the size of piece and treating each grade separately by charging a suitable quantity of the same together with a flux into a heating and welding furnace and so manipulating the charge that the pieces will become alternately submerged in the flux and then removed therefrom, meanwhile subjecting. the charge to a rising temperature suflicient to reduce it to a homogeneous mass or ball, and then removing the ball and subjecting it to a pressure by squeezing or hammering to produce a bloom or billet, substantially as described.

MALCOLM MCDOVELL. 

